He recommends walking in truth, loving one another and to beware of false teachers.

[1]The ancientto the lady Elect, and her children, whom I love in the truth, and not I only, but also all they that have known the truth,
[2] For the sake of the truth which dwelleth in us, and shall be with us for ever.
[3] Grace be with you, mercy, and peace from God the Father, and from Christ Jesus the Son of the Father; in truth and charity.
[4] I was exceeding glad, that I found of thy children walking in truth, as we have received a commandment from the Father.
[5] And now I beseech thee, lady, not as writing a new commandment to thee, but that which we have had from the beginning, that we love one another.

[1] "The ancient": That is, the ancient bishop St. John, being the only one of the twelve apostles then living.

[1] "To the lady Elect": Some conjecture that Elect might be the name of a family, or of a particular church; but the general opinion is, that it is the proper name of a lady, so eminent for her piety and great charity, as to merit this Epistle from St. John.

[6] And this is charity, that we walk according to his commandments. For this is the commandment, that, as you have heard from the beginning, you should walk in the same:
[7] For many seducers are gone out into the world, who confess not that Jesus Christ is come in the flesh: this is a seducer and an antichrist.
[8] Look to yourselves, that you lose not the things which you have wrought: but that you may receive a full reward.
[9] Whosoever revolteth, and continueth not in the doctrine of Christ, hath not God. He that continueth in the doctrine, the same hath both the Father and the Son.
[10] If any man come to you, and bring not this doctrine, receive him not into the house nor say to him, God speed you.

[10] "Nor say to him, God speed you": This admonition is in general, to forewarn the faithful of the dangers which may arise from a familiarity with those who have prevaricated and gone from the true faith, and with such as teach false doctrine. But this is not forbidding a charity for all men, by which we ought to wish and pray for the eternal salvation of every one, even of our enemies.

[11] For he that saith unto him, God speed you, communicateth with his wicked works.
[12] Having more things to write unto you, I would not by paper and ink: for I hope that I shall be with you, and speak face to face: that your joy may be full.
[13] The children of thy sister Elect salute thee.